Threestage gear unit sizes to Threestage gea B3-VH-13-D Bevel-helical gear Reduction Boxes B3

Flender/Flender Gear Units/Bevel-helical gear Reduction Boxes B3

oncentrations TCOD mg/ 4 5 4 1,0 TKN mgN/ 3 3 3 FSA mgN/ 2 2 2 Total mgP/ 4.5 4.4 4.5 Ortho mgP/ 2.6 2.5 2.5 TSS mg/ 1 1 1 PST Removal Rates COD % 3 TKN % 9.4 Total % -5 TSS % 6 Table 5-4: Average Wastewater Characteristics (based on data collected during the 2 and 2 special sampling programs) Parameter Symbol Raw Settled Wastewater Characteristic Fractions BO (SB)/Total (St) FSbi 0.7 0.8 BPO (Sbp)/Total (St) FSbpi 0.5 0.4 BSO (Sbs)/Total (St) FSbsi 0.2 0.3 VFA (Sa/Total (St) FSai 0.0 0.0* USO (Sus)/Total (St) FSusi 0.0 0.1 UPO (Sup)/Total (St) FSupi 0.1 0.0* Nitrogen Fractions FSA/TKN Fnai 0.6 0.0 Phosphorus Fractions Ortho /Total 0.5 0.6 Other Fractions TKN/COD 0.0 0.7 Total /COD 0.1 0.1 VSS/TSS 0.1 The wastewater characteristics and fractions fall within the generally expected ranges for South African municipal wastewater. It should be noted that the average values in Table 5-4 were deduced from rigorous data reconciliation process combining both statistical analysis of measured data and steady state activated sludge modelling. 5-7 Figure 5-3: JP Marais WWTP 2 Influent Flow and Loads 5-8 5.4.2 Baseline Plant Operation and Performance Operating Parameters Waste activated sludge is extracted from the last cell of the bioreactor by two pumps. It was reported that from April to May 2, one WAS pump was out of service. Although there is flow meter to record WAS wastage, there was very few recorded data to give an accurate indication of the process operating sludge age. The average MLSS concentratio from January to August, with the Welgedacht flow, was 3,5 mg/ which indicates an average sludge age of about 1 days. From September to December, the average MLSS concentration increased to 5,0 mg/ which indicates an operating sludge age of about 2 days. Similarly, although the RAS pumps are equipped with flow meters, very litt